Comparison of 3M-PetrifilmTM and conventional methods for quick counting of aerobics on confectionery products
Keywords:
Confectionery products, 3M-Petrifilm, counting of aerobicsAbstract
As a requirement to evaluate the quality of food products, the counting of aerobic mesophilic microorganism is used. Effectiveness of applying a fast methodology in order to detect the existence of these microorganisms is crucial to take corrective actions in processing facilities. This study aimed to compare the alternative method 2015.13 AOAC vs the traditional method based on tryptone soy agar for aerobes fast counting confectionery products. The matrix chocolate coating was internally inoculated with Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. The matrix cocoa powder showed natural contamination. 5 levels of inoculum were tested: 60, 380, 700, 36 000, 40 000 UFC/g. The culture temperature was about 35°±1°C during 24±2 hours for the method AOAC 2015.13 and 48±2 hours for the conventional method. Results demonstrated that there are no statistical difference between matrixes based on chocolate coatings and cocoa powder, on 3M-PetrifilmTM and tryptone soy agar plates, for aerobes fast counting with inocula 60 (p=0,506), 380 (p=0,843), 700 (p=0,378), 36 000 (p=0,180) and 40 000 (p=0,180), with a correlation coefficient of r=0.99 (p≤0.05), precision Rp%≤2.0*RDS%Poison and recovery ≥ 80%. The 3M-PetrifilmTM RAC Alternative Microbiological Counting Method has been shown to be reproducible, reliable, and accurate.
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